Economical pump

ABSTRACT

A fluid pump can include one section which reciprocates relative to another section, whereby fluid is pumped between the sections. The fluid pump can be devoid of any dynamic seal. Each of the pump sections can include a check valve. Structural components of the pump can be made of a non-metal material. One section can be received in a bore of the other section, and a relatively small gap between the bore and the one section can allow minimal leakage of the fluid between the bore and the one section.

BACKGROUND

This disclosure relates generally to fluid pump construction and, in anexample described below, more particularly provides an economicallyconstructed pump.

In some economically disadvantaged areas, such as central Africa,Honduras, etc., water is not readily available for human consumption orirrigation, due in large part to the fact that equipment needed to pumpthe water from its source (such as, an underground aquifer) is beyond alocal population's means. Therefore, it will be appreciated that aninexpensive pump that can be easily installed and operated would be verybeneficial to such an economically disadvantaged population.

There are other situations, also, in which an economical pump would beof benefit. For example, in some oil fields only marginal production isrealized, and so it does not make economic sense to install veryexpensive pumping equipment. In those situations, the availability of aninexpensive pump would make a difference between whether or not thefield is produced.

Thus, for these reasons and others, the art would be enhanced ifeconomical construction of a fluid pump could be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative partially cross-sectional view of a wellsystem and associated method which can embody principles of thisdisclosure.

FIG. 2 is an enlarged scale representative cross-sectional view of apump which can embody principles of this disclosure, the pump beingdepicted in a fluid lifting configuration.

FIG. 3 is a representative cross-sectional view of the pump in a fluidreceiving configuration.

FIG. 4 is a representative cross-sectional view of another example of areciprocating section of the pump.

FIG. 5 is a representative side view of another example of thereciprocating section of the pump.

DETAILED DESCRIPTION

Representatively illustrated in FIG. 1 is a system 40 for use with awell, and an associated method, which system and method can embodyprinciples of this disclosure. However, it should be clearly understoodthat the system 40 and method are merely one example of an applicationof the principles of this disclosure in practice, and a wide variety ofother examples are possible. Therefore, the scope of this disclosure isnot limited at all to the details of the system 40 and method describedherein and/or depicted in the drawings.

In the FIG. 1 example, a fluid pump 10 is installed in a wellbore 42,and is in fluid communication with a surface location via a pipe 28. Atthe surface location, a reciprocation device 44 is used to upwardly anddownwardly displace the pipe 28, thereby operating the pump 10, so thatfluid 36 from an earth formation 46 is pumped to the surface locationvia the pipe.

In FIG. 1, the reciprocation device 44 is depicted as being a pump jackof the type typically used in oil fields to pump hydrocarbons tosurface. However, in other examples, the reciprocation device 44 couldbe a windmill, a hand-operated lever or crank, or any other devicecapable of reciprocating the pipe 28 in the wellbore 42. Thus, the scopeof this disclosure is not limited to use of any particular type ofreciprocation device.

Referring additionally now to FIGS. 2 & 3, enlarged scalecross-sectional views of the pump 10 are representatively illustrated,apart from the remainder of the system 40. Note that the pump 10 may beused with other well systems, in keeping with the principles of thisdisclosure.

In FIG. 2, the pump 10 is depicted in a configuration in which the pipe28 is being displaced upward, and the fluid 36 is flowing into the pump.In FIG. 3, the pump 10 is depicted in a configuration in which the pipe28 is being displaced downward, and the fluid 36 is flowing from thepump into the pipe.

The pump 10 as illustrated in FIGS. 2 & 3 can be constructed mainly ofnon-metal materials (such as, common PVC (polyvinyl chloride) pipe,etc.), and can be assembled and operated without use of any dynamicseals (e.g., without relative motion between a seal and a surfaceagainst which the seal seals). However, metal materials and dynamicseals may be used in some examples.

In the FIGS. 2 & 3 example, components of the pump 10 include a bottomseat 12, balls 14, 16, casing 18, lower bushing 20, upper seat 22, pumpbushing 24, lower seat casing 30 and a threaded connector 26 forattachment of the pump to pipe 28. The lower seat 12 and ball 14comprise a lower check valve 48, and the upper seat 22 and ball 16comprise an upper check valve 50.

Note that, in the FIG. 2 configuration, the upper check valve 50 isclosed, thereby drawing the fluid 36 into the pump 10 as the pipe 28 israised, and the lower check valve 48 is open, thereby allowing the fluidto enter the pump. In the FIG. 3 configuration, the lower check valve 48is closed, thereby preventing the fluid 36 from flowing downwardly outof the pump 10 as the pipe 28 is lowered, and the upper check valve 50is open, thereby allowing the fluid to flow from the pump into the pipe.

The balls 14, 16 are preferably made of stainless steel, but othermaterials may be used, if desired. The bottom seat 12, casings 18, 30,32, lower bushing 20, upper seat 22, pump bushing 24 and threadedconnector 26 are preferably made of PVC material.

The casings 18, 30, 32, lower bushing 20, pump bushing 24 and threadedconnector 26 can be made from industry standard PVC pipe and fittings,thus making the pump 10 very economical to inventory and manufacture.The non-metal components can be quickly and conveniently glued together,thus making the pump 10 very economical to assemble.

The lower seat 12 allows fluid 36 to enter a variable volume pumpchamber 34 from an earth formation (e.g., a water aquifer or hydrocarbonreservoir) by upward displacement of the pipe 28 (as depicted in FIG.2), which enlarges the volume of the chamber. Upon downward displacementof the pipe 28 (as depicted in FIG. 3), the chamber 34 volume decreases,and the fluid 36 is transferred from the chamber into the pipe.

This pumping process is accomplished, in this example, by using closetolerances resulting in a very small gap between two sizes of PVC pipemaking up the casings 18, 32, and without use of any dynamic seals. ThePVC pieces are machined to different tolerances depending on the actualsizes of PVC used for the pump 10 and pipe 28. Although a small amountof leakage occurs between the casing 32 and an inner bore 52 of thecasing 18 when the chamber 34 expands and contracts, sufficient pressuredifferential can be created to flow the fluid 36 into the pump 10, andthen into the pipe 28.

The PVC pipe used in the construction of this pump 10 can be acombination of schedule 40 pipe and schedule 80 PVC pipe to obtaindesired tolerances for each nominal size pump. A smaller PVC piece(e.g., casing 32) slides inside a slightly larger piece (e.g., casing18) to enable the pumping action. Thus, an upper section 54 (comprisingthe upper connector 26, casing 32, bushing 24 and check valve 50)reciprocates relative to a lower section 56 (comprising the casing 18,bushing 20, casing 30 and check valve 48) to pump the fluid 36, withoutuse of any dynamic seal between the sections.

The top connector 26 is preferably threaded and glued to PVC pipe 28,although other materials and connection methods may be used, in keepingwith the principles of this disclosure. No additional seal or packingmaterial is needed to perform the pumping process. No electricity isrequired for the operation of this pump (although electricity could beused to power a motor to reciprocate the pipe 28, if desired).

Note that it is not necessary for the upper section 54 to reciprocatewithin the lower section 56 since, in other examples, a lower end of theupper section could outwardly overlap an upper end of the lower section56. Thus, the scope of this disclosure is not limited to any particulardetails of the pump 10 as depicted in FIGS. 2 & 3.

Referring additionally now to FIG. 4, another example of the uppersection 54 is representatively illustrated. In this example, the uppersection 54 can be made entirely or mostly of metal, so that it is morewear resistant and suitable for, e.g., oil field applications,situations where the fluid 36 may be somewhat abrasive, etc. Althoughnot shown in FIG. 4, the lower section 56 can be similarly constructedentirely or mostly of metal.

In the FIG. 4 example, the threaded connector 26 is internally threadedfor 1″ line pipe, but other types of threads may be used, if desired. Inaddition, the pump bushing 24 is replaced by a pin 58 disposedtransversely through the casing 32, and the pin is welded, threaded,press-fit or otherwise secured in place.

The seat 22 is retained between two threaded together sections 32 a,b ofthe casing 32. This demonstrates that the scope of this disclosure isnot limited to use of PVC or any other non-metal material in the pump10. Any suitable material may be used for any component(s) of the pump10, in keeping with the principles of this disclosure.

Referring additionally now to FIG. 5, a side view of another example ofthe upper section 54 is representatively illustrated. In this view, itmay be seen that a plurality of radially reduced annular grooves orrecesses 60 are formed on an exterior of the casing 32. These grooves orrecesses 60 may be helpful to reduce leakage between the casings 18, 32,for example, by increasing resistance to flow through the gap betweenthe casing 32 and the bore 52 of the casing 18 in which it reciprocates.

In addition, the grooves or recesses 60 may be helpful to prevent sandand/or debris from passing between the casings 32, 18, for example, byincreasing turbulence in the gap between the casings. However, thegrooves or recesses 60 are not necessary in keeping with the scope ofthis disclosure.

It may now be fully appreciated that the above disclosure providessignificant advances to the art of economically constructing fluidpumps. In examples described above, the pump 10 can be economicallymanufactured and assembled, and can operate reliably for a extendedperiod of time due to an absence of any dynamic seals in the pump.

The above disclosure provides to the art a fluid pump 10. In oneexample, the pump 10 can include a first section 54 which reciprocatesrelative to a second section 56, whereby fluid 36 is pumped between thefirst and second sections 54, 56. The fluid pump 10 may be devoid of anydynamic seal.

The first section 54 may be received in a bore 52 of the second section56, and a relatively small gap between the bore 52 and the first section54 may allow only minimal leakage of the fluid 36 between the bore 52and the first section 54.

Each of the first and second sections 54, 56 can include a check valve48, 50. In some examples, the check valve 48, 50 can include a ball 14,16 which seals against a non-metal seat 12, 22. The ball 14, 16 may becontained in a non-metal casing 30, 32.

The first section 54 may be received in a bore 52 of the second section56, and recesses 60 formed on an outer surface of the first section 54may reciprocate in the bore 52. A volume of a chamber 34 of the pump 10may vary in response to reciprocation of the first section 54 relativeto the second section 56.

Although various examples have been described above, with each examplehaving certain features, it should be understood that it is notnecessary for a particular feature of one example to be used exclusivelywith that example. Instead, any of the features described above and/ordepicted in the drawings can be combined with any of the examples, inaddition to or in substitution for any of the other features of thoseexamples. One example's features are not mutually exclusive to anotherexample's features. Instead, the scope of this disclosure encompassesany combination of any of the features.

Although each example described above includes a certain combination offeatures, it should be understood that it is not necessary for allfeatures of an example to be used. Instead, any of the featuresdescribed above can be used, without any other particular feature orfeatures also being used.

It should be understood that the various embodiments described hereinmay be utilized in various orientations, such as inclined, inverted,horizontal, vertical, etc., and in various configurations, withoutdeparting from the principles of this disclosure. The embodiments aredescribed merely as examples of useful applications of the principles ofthe disclosure, which is not limited to any specific details of theseembodiments.

In the above description of the representative examples, directionalterms (such as “above,” “below,” “upper,” “lower,” etc.) are used forconvenience in referring to the accompanying drawings. However, itshould be clearly understood that the scope of this disclosure is notlimited to any particular directions described herein.

The terms “including,” “includes,” “comprising,” “comprises,” andsimilar terms are used in a non-limiting sense in this specification.For example, if a system, method, apparatus, device, etc., is describedas “including” a certain feature or element, the system, method,apparatus, device, etc., can include that feature or element, and canalso include other features or elements. Similarly, the term “comprises”is considered to mean “comprises, but is not limited to.”

Of course, a person skilled in the art would, upon a carefulconsideration of the above description of representative embodiments ofthe disclosure, readily appreciate that many modifications, additions,substitutions, deletions, and other changes may be made to the specificembodiments, and such changes are contemplated by the principles of thisdisclosure. For example, structures disclosed as being separately formedcan, in other examples, be integrally formed and vice versa.Accordingly, the foregoing detailed description is to be clearlyunderstood as being given by way of illustration and example only, thespirit and scope of the invention being limited solely by the appendedclaims and their equivalents.

What is claimed is:
 1. A fluid pump, comprising: a first section whichreciprocates relative to a second section, whereby fluid is pumpedbetween the first and second sections, and wherein the fluid pump isdevoid of any dynamic seal.
 2. The fluid pump of claim 1, wherein thefirst section is received in a bore of the second section, and arelatively small gap between the bore and the first section allowsminimal leakage of the fluid between the bore and the first section. 3.The fluid pump of claim 1, wherein each of the first and second sectionscomprises a check valve.
 4. The fluid pump of claim 3, wherein the checkvalve comprises a ball which seals against a non-metal seat.
 5. Thefluid pump of claim 4, wherein the ball is contained in a non-metalcasing.
 6. The fluid pump of claim 1, wherein the first section isreceived in a bore of the second section, and wherein recesses areformed on an outer surface of the first section, whereby the recessesreciprocate in the bore.
 7. The fluid pump of claim 1, wherein a volumeof a chamber of the pump varies in response to reciprocation of thefirst section relative to the second section.
 8. A fluid pump,comprising: a first section which reciprocates relative to a secondsection, whereby fluid is pumped between the first and second sections,and wherein each of the first and second sections comprises a checkvalve.
 9. The fluid pump of claim 8, wherein the fluid pump is devoid ofany dynamic seal.
 10. The fluid pump of claim 8, wherein the firstsection is received in a bore of the second section, and a relativelysmall gap between the bore and the first section allows minimal leakageof the fluid between the bore and the first section.
 11. The fluid pumpof claim 8, wherein the check valve comprises a ball which seals againsta non-metal seat.
 12. The fluid pump of claim 11, wherein the ball iscontained in a non-metal casing.
 13. The fluid pump of claim 8, whereinthe first section is received in a bore of the second section, andwherein recesses are formed on an outer surface of the first section,whereby the recesses reciprocate in the bore.
 14. The fluid pump ofclaim 8, wherein a volume of a chamber of the pump varies in response toreciprocation of the first section relative to the second section.
 15. Afluid pump, comprising: a first section which reciprocates relative to asecond section, whereby fluid is pumped between the first and secondsections, and wherein the first section is received in a bore of thesecond section, and a relatively small gap between the bore and thefirst section allows minimal leakage of the fluid between the bore andthe first section.
 16. The fluid pump of claim 15, wherein the fluidpump is devoid of any dynamic seal.
 17. The fluid pump of claim 15,wherein each of the first and second sections comprises a check valve.18. The fluid pump of claim 17, wherein the check valve comprises a ballwhich seals against a non-metal seat.
 19. The fluid pump of claim 18,wherein the ball is contained in a non-metal casing.
 20. The fluid pumpof claim 15, wherein recesses are formed on an outer surface of thefirst section, whereby the recesses reciprocate in the bore.